1. Field of the Invention
The present invention relates generally to pressure relieving rupture disk assemblies, and more particularly, to an improved low pressure relieving rupture disk assembly wherein a blow-out part is at least partially defined by one or more perforations.
2. Description of the Prior Art
Many rupturable pressure relief devices have been developed and used heretofore. Generally, such devices have included a rupture disk supported between a pair of support members or flanges which are in turn connected to a relief passageway in a vessel or system containing fluids under pressure. When the fluid pressure within the vessel or system exceeds the predetermined rupture pressure of the disk, rupture occurs causing pressurized fluid to be relieved from the vessel or system.
Rupture disks of the reverse buckling type have heretofore been developed and used successfully. Reverse buckling rupture disks generally include a dome-shaped portion and the fluid pressure from the vessel or system being protected is exerted on the convex side of the disk. Upon failure, the dome-shaped portion reverses and then ruptures. Originally, all reverse buckling rupture disk assemblies included knife blades positioned adjacent the rupture disks thereof on the outlet sides of the disks. On reversal, the disks impaled on the knife blades causing them to open in a predetermined manner. More recently, reverse buckling rupture disks have included scores on a surface thereof which create lines of weakness therein so that upon reversal, the disks tear along the lines of weakness.
U.S. Pat. No. 3,294,277 issued Dec. 27, 1966 to Wood describes a reverse buckling rupture disk with knife blades. U.S. Pat. No. 3,484,817 issued Dec. 16, 1969 to Wood describes the construction and operation of scored reverse buckling rupture disks. A method of manufacturing scored reverse buckling rupture disks is described in U.S. Pat. No. 3,921,556 issued Nov. 25, 1975 to Wood et al. U.S. Pat. No. 5,167,337 issued Dec. 1, 1992 to Short et al. describes a C-scored reverse buckling rupture disk assembly for high pressure applications including means for catching and supporting the hinge area of the blow-out part formed by the C-shaped score.
While scored reverse buckling rupture disks have been used successfully and have obviated the need for knife blades in high pressure applications, scored reverse buckling rupture disks have only achieved varying degrees of success in low pressure applications. Consequently, knife blades have still had to be utilized with reverse buckling rupture disks utilized in such low pressure applications. The inclusion of the knife blades causes the resulting rupture disk assemblies to be relatively expensive.
Thus, there is a need for an improved rupture disk assembly which can be utilized in low pressure applications without the need for knife blades or the like.